Photonics Research, Volume. 13, Issue 7, 1991(2025)
Spiral resonator referenced low noise microwave generation via integrated optical frequency division
Fig. 1. (a) Spiral resonator referenced on-chip low noise microwave generation architecture based on integrated optical frequency division. The lasers are locked to two cavity modes of an ultra-high-
Fig. 2. (a) Beat note phase noise of co-PDH locked lasers (blue) and free-running lasers (red). Relative phase noise of the co-PDH locked laser to the spiral resonator is reduced below the cavity TRN noise limit (which is shown as the green curve). (b) Comparison of on-chip low noise dual laser references. The current work has achieved record low on-chip relative laser phase noise from 10 Hz to 10 kHz offset. (i) Two lasers co-self-injection-locked to a
Fig. 3. (a) Broadband integrated EO comb spectrum with 3 dB bandwidth of 4.4 THz is generated from the tandem TFLN PM chip. (b) Optical spectra of the co-PDH locked lasers spanning 27 nm (red), and the TFLN EO comb (blue) under eOFD operation. Inset shows the zoom-in EO comb lines at the spectral middle point between the two lasers.
Fig. 4. (a) Schematic of the experimental setup for the chip-based PMO. (b) Microwave phase noise of the chip-based PMO at 37.3 GHz carrier (blue). The dashed green curve is the phase noise of the 10 GHz carrier scaled from the 37.3 GHz PMO output. Yellow curve is the phase noise of the co-PDH locked lasers. Brown curve is the phase noise of the free running VCO at 37.3 GHz. Dashed black curve is the projected PMO phase noise by scaling down the co-PDH locked laser phase noise by 39 dB. Insets are the RF spectra for the PMO in locked (RBW 2 Hz) and free-running cases (RBW 1 kHz).
Fig. 5. Residual PDH locking phase noise is plotted (black curve) for one of the external cavity diode lasers (RIO laser) when it is locked to the 14 m
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Long Cheng, Mengdi Zhao, Yang He, Yu Zhang, Roy Meade, Kerry Vahala, Mian Zhang, Jiang Li, "Spiral resonator referenced low noise microwave generation via integrated optical frequency division," Photonics Res. 13, 1991 (2025)
Category: Integrated Optics
Received: Mar. 20, 2025
Accepted: Apr. 29, 2025
Published Online: Jul. 2, 2025
The Author Email: Jiang Li (jiang.li@hqphotonics.net)
CSTR:32188.14.PRJ.562434